On the eigenvalue analysis using HH-VV dual-polarization SAR data and its applications to monitoring of coastal oceans

Abstract

In the conventional SAR (Synthetic Aperture Radar) polarimetry, fully polarimetric HH-HV-VH-VV quad polarization data are used. The advantage of using quad-polarization data is more information on the scattering objects than the single- and quad-polarization data; while the disadvantages are narrower swath and less frequent data takes. To fill the gap in-between, the present study examines the polarimetric analysis using HH-VV dual polarization. The model-based three- and four-component scattering power decomposition analyses are not possible with dual-polarization data, and thus, the study is focused on the eigenvalue decomposition analysis by comparing the entropy and mean alpha angle derived from dual-polarization data with those derived from quad polarization data, acquired by ALOS-PALSAR (Advanced Land Observing Satellite Phased Array L-band SAR) PLR (PoLaRimetric mode) and TerraSAR-X dual-polarization SpotLight mode over the Tokyo Bay, Japan. The preliminary results indicate that the values of dual-polarization entropy and alpha angle are almost the same as the quad-polarization values, indicating that dual-polarization data are as capable as quad-polarization data in the eigenvalue decomposition. The technique is then applied to estimating the underwater laver cultivation fields and ship detection.